Explanation:

- The forests of Uttarakhand, Kullu Valley in Himachal Pradesh, and Dzukou Valley in Nagaland and Manipur have been in the news for various environmental issues.

- Option 1: Deforestation

This refers to the large-scale removal of trees, which can threaten biodiversity. However, this is not the primary reason these forests were in recent news.

- Option 2: Forest fire

Forest fires are a significant concern in these regions. They can devastate wildlife and vegetation, affecting the ecosystem.

- Option 3: Poaching of wild animals

This is an illegal activity that threatens wildlife, but it's not the main issue recently highlighted for these specific forests.

- Option 4: Illegal mining

Mining can lead to environmental degradation, though it hasn't been the primary reason for news in these forest areas.

Your Answer: Option 2 - Forest fire is correct.